1. Field of the Invention
The invention relates to batteries, and, in particular, to button cells.
2. Description of the Related Art
Voltaic cells, especially in the form of button cells, consist of a housing cup and a lid. The housing cup is manufactured, for example, from nickel-plated deep-drawn sheet metal as a stamped part. Ordinarily, the housing cup is the positive pole and the lid is the negative pole. Such button cells may contain a great variety of electrochemical systems, such as nickel/cadmium, nickel/metal hydride, or a variety of primary systems such as zinc/MnO.sub.2 or primary and secondary lithium systems.
The liquid-tight sealing of such cells is accomplished by flanging the edge of the cup over the edge of the lid; in this case, a plastic ring serves as both a sealing ring and as insulation of the cup against the lid. Such button cells are known, e.g., from German Patent DE-OS 3113309.
The sealing elements required for these button cells are produced by the injection molding process, e.g., from polyamides. The injection tools required for this process are very costly. In addition, it is practically impossible to produce sealing elements with walls of a thickness of less than 0.3 mm by the injection molding process so that the known seals, especially in the case of very small button cells, require a relatively large volume and therefore limit the utilization of the cell capacity.